p-51 progress and pics - RC Groups
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Oct 11, 2002, 12:16 AM
Motors beat engines!

p-51 progress and pics

Finally got a chance to work on my jk aerotech p-51. The wings all done except for adding the servo, and the fuse is 90% sanded to shape.

I have abandened my original sp480 3:1 9x7 on 10 600ae drivetrain for one that seems more promising. Its an atomic force 2.5:1 with the same 9x7 folder but on 6 1500 scr's, a $10 car pak.

Motocalc predicts a over 1000 ft/min climb, top speed in the mid 50's and flights around 5-6 minutes with a little throttle control. If I like its performance enough, I might splurge and get some 3000 nimh paks. About the same weight, but flight times would double.

Anyway, heres the grainy pics. ( cheap camera )

Dean in Milwaukee
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Oct 11, 2002, 12:17 AM
Motors beat engines!
One more:
Oct 11, 2002, 01:01 AM
tic's Avatar
cool Dean, let us know how she flies
Oct 11, 2002, 01:51 AM
Registered User
looks great dean let me know how she flys when she is done, or better yet let me know where you do your flying and ill be there im about 5 min. west of menomonee falls and thats only a hop&skip from where ever you fly. maybe we can hook up and do some flying & electric talk, i have a nice little fleet of electric planes and always like to hook up with someone local and bird talk.....
Oct 11, 2002, 09:52 AM
Motors beat engines!

Thanks and I will definately post about its flights, and I will be doing more construction photos too as I progress.


I fly at the County field at 68th and oakwood. Oakwood is the next street south of Ryan.

I'd be happy to meet you and fly with you too. At my field though, you do need an ama card, but I can bring you in as a guest too. I actually live near Summerfest, so maybe I could come out and fly with you too. Where do you fly?
Your right about finding others who e-fly. We're still fairly unusual around here.

Dean in Milwaukee
Oct 12, 2002, 01:44 PM
Motors beat engines!

progress and more pics

Have made some progress, and have enclosed some detail pics.

First pic is of my coroplast motor mount. Its the same setup I use on my gravity abuse plane. Very lightweight and sturdy, and allows simple motor thrust changes.

It consists of a piece of coroplast, folded into a u shape, and thinned where it meets the motor. A hose clamp holds the motor to it, hot glue and fiber tape holds it to the fuse. Very tough!
Last edited by DeaninMilwaukee; Oct 12, 2002 at 03:03 PM.
Oct 12, 2002, 01:50 PM
Motors beat engines!
Second pic is my lexan cowl made by heat shrinking a 2 litre coke bottle over a wooden form with a heat gun on low. This one is'nt quite right yet, I need to do some more sanding on the wood form.

Side view:
Last edited by DeaninMilwaukee; Oct 12, 2002 at 01:54 PM.
Oct 12, 2002, 01:52 PM
Motors beat engines!
Front view of same:
Oct 12, 2002, 02:00 PM
Motors beat engines!
Here it is assembled with spinner. Can see pretty much how its going to look here.
Oct 13, 2002, 01:58 AM
Winter Sucks!!
romans1015's Avatar
Hi Dean,
Looks like you have been busy. Something to do on those windy days. I'd like to see that P51 when your done. Especially interested in how you mounted your motor. Let me know when you go out. I'm still interested.
Happy building.

Oct 13, 2002, 10:49 AM
Motors beat engines!
I will be sure to let you know when I go. Fact is, I've barely flown at all since that fun fly. Always a matter of weather sucking whenever I'm free to go.

Ah well, thats one of the nice things about electrics, they could care less if its cold out, so the flying season never really ends!

The motor mount really is simple. The pic did'nt show nearly the detail that I thought it would unfortunately, but where the strength comes from is the fact that the coroplast is very tough, yet flexable, allowing it to absorb inpacts by letting the motor move, ( and then snap back) on impact, and the coroplast is held to the fuse by both epoxy or hot glue, and a band of fiber tape across it wrapping back down the sides of the fuse, and a band of the tape then wrapped around the fuse making sure that the first strip can't come loose either.

I developed this mount for my Gravity Abuse pattern plane, and wound up testing it when a hs55 elevator servo stripped out in flight leading to a 50 mph pile in at around 30 degrees.

The only damage turned out to be a broken prop and the exit hole the 17 oz battery made on the way out. Everything else held up fine, including the lexan cowl I have on that plane too. Lexan is very tough stuff too!

Dean in Milwaukee
Oct 19, 2002, 02:33 AM
Motors beat engines!
Almost done finally! Just need to wait for Goop to dry so I can locate the battery and make its hatch and I'm done. I wound up using a 7 cell rc 1700 pak I got from dymond cheap.

Motocalc says 30 amps and the 9x7 folder really winds up and screams! I'm certain power will not be a problem.

Heres a poor pic. Not enough light.

Dean in Milwaukee
Last edited by DeaninMilwaukee; Oct 19, 2002 at 02:36 AM.
Oct 19, 2002, 10:10 AM
Giddy up!
Sal C's Avatar

Nice job! You're very good at building those JKA warbirds. Let us know how it flies, good luck. Are you hand launching?
Oct 19, 2002, 02:45 PM
Motors beat engines!
Thanks Sal.

I did get one flight in today despite the winds. Really should'nt have tried, but what the heck.

Turns out its much easier to launch than my Zero was, both because its lighter at 41 oz vs 50 and also because the mustang has that nice scoop on the bottom that lets you hold the plane properly for a decent throw.
The Zero forced you to hold it behind the wing, and the fuse was so wide and rounded you had a tough time grasping it properly. 1/3rd of my zero throws twisted on release making an automatic crash. The p-51 is MUCH easier to throw.

This powertrain BTW, is quite good. My first flight ever lasted about 6.5 minutes, and power did'nt fade much till 6 minutes. Mostly wide open too. Fast and lots of climb.

Roll rate was quite good, but I did set aileron deflection for about 40 degrees. Elevator, like the zero's needs very little throw to perform.

I did have a problem of climbing under power, but when I go home I realized I had actually given it some UP thrust.

Ok ok, I finished this sucker up at 1:30 am. Bound to miss something when your that tired.

More flight reports and pics soon, but I think this plane and drivetrain will be winners.

Dean in Milwaukee
Oct 20, 2002, 07:32 PM
Motors beat engines!

Flight impresions then disaster!

Wind was much better today, got 5 flights in on the p51.

Impressions: Power is plentiful for making launching easy. It does need a good throw, but thats no problem holding onto the bottom scoop. Rolls are very fast, inverted is ok, no great, elevator seemed to lack power at lower speeds.

Speed is around mid 50's. Had little trouble keeping up with the .40 powered high wings there, but speed is'nt spectacular. Climb is pretty good, but definately done " on the wing".

I was able to swoop in low and fast, pull up to vertical and get in about 10 or so rolls before speed bled of completely. Overall, vertical is pretty decent and better than most of the gas planes. there today. I ran mostly wide open, and was about done at 5 minutes per my timer. Not too bad for rc 1700's. With the new 3300 nimhs, the planes duration should easily beat mine.

Landings were pretty easy, it just floats on in and retains speed well. It seems like drag is fairly low. Touch down causes the scoop to dig in, but no damage results so no problem. I suspect my cg was just about perfect.

Last flight of the day, I was going to do a big round 1/2 loop coming almost right for the pits, got some speed up, dove towards myself and pulled up hard, but the plane did'nt go up, it instead snapped out hard, going inverted at about 60 mph right at the pits with little time to think.

Did I mention that the pits were somewhat croweded?

I almost managed to save it, steering away but stalling a wing again and ultimately going in inverted pretty hard just outside the pits.

The fuse is busted up pretty bad in the middle where the battery was, actually its in pieces. The nose and tail are virtually unscathed, but the middle section is blown apart pretty bad. Luckily its all big pieces and 1/2 dozen glue sticks and some more tape should make it whole again. Luckily its a foamie!

PS, anybody know how to solve a snapping problem. Throw is not big here at all, only about 1/4 up and down.

Dean in Milwaukee

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